Gulf flounder - flounder world

• Brown body color, with numerous spots and blotches
• Three prominent dark, eyelike spots forming a triangle-shape (one spot on lateral line, one above and one below)
• Numerous white spots scattered throughout body and fins
• Belly is white or dusky
• Strong canine-like teeth
• Wedge-shaped tail, its tip in the middle

The Gulf flounder is a flatfish that swims on its side. Their two eyes look upward when swimming. They have sharp teeth, two eyes on one side, and have a white side. Paralichthys albigutta is widely distributed in the western North Atlantic. Adults are found in a variety of habitats, but generally prefer hard, sandy bottoms; juveniles settle in high salinity seagrass beds. Longevity is 7–10 years and females reach maturity between 1–2 years. It is commercially and recreationally exploited. The center of abundance of Paralichthys albigutta in the Gulf of Mexico is along the northeastern coast of Florida. West of the Mississippi River delta, it occurs in very low numbers.It appears to naturally occur in low abundance in seagrass beds. It is common in museum collections (660 lots). Many species of fishes, including P. albigutta, have experienced declines in abundance in the Northern Gulf of Mexico from 1970-2000; although Fodrie et al. (2010),(This needs to be challenged, as in coastal Western Louisiana, the flounder have not been as plentiful in 50 years, as of 2018), attributed this at least in part to the effects of global rises in sea temperature, there are also a number of other factors (e.g., bycatch in trawl fisheries, increased recreational landings: T. Munroe pers. comm. 2015) that may contribute to these declines. Gill netting has been implicated in the decline of flounder stocks in North Carolina due to targeting of non-reproductive juveniles; however, the population-level effects of this method of harvest on P. albigutta are unknown 

Flounder inhabit a wide variety of coastal habitats including brackish water rivers, tidal creeks, bays, estuaries, beaches, muddy or sandy bottoms and near-shore rocky bottoms. Anglers generally use light spinning tackle and often target flounder close to shoreline structure including stumps, dock piles, seawalls and bridge piles, which are good points of ambush. While flounder can be caught with a wide variety of natural or artificial baits, most anglers prefer to use live mud minnows, live finger mullet, live or frozen shrimp, cut bait or jigs. Flounder are ambush predators that feed primarily by sight - so it is often helpful to periodically bump the bait across the bottom to make it more visible. Flounder can also be taken with a gig in shallow waters, especially at night with the use of a lantern.

   Scientific classification  

Kingdom:        Animalia

Phylum:     Chordata

Class:      Actinopterygii

Order:    Pleuronectiformes

Family:   Paralichthyidae

Genus:  Paralichthys

Gulf flounder appear to prefer the ocean floor and camouflage against areas to stealthily strike their prey. This demersal species occurs in shallow depths within estuaries and coastal environments; it is most commonly found on the continental shelf at depths of 18–92 m, but has been collected to about 130 m.

VIDEO

Winter flounder

The name 'winter' flounder refers to their annual spawning migrations into nearshore waters in winter. Adults migrate in two phases; an autumn estuarine immigration prior to spawning, and a late spring/summer movement to either deeper, cooler portions of estuaries or to offshore areas after spawning. This pattern of seasonal distribution may change in colder waters at the northern extent of their range where winter flounder migrate to shallow waters in the summer and deeper waters in the winter. The annual spawning period varies geographically and although spawning periods overlap considerably, peak spawning times are earlier in southern locations.

During spawning, females release demersal (negatively or neutrally buoyant) adhesive eggs whose properties facilitate retention within spawning grounds. Many factors influence larval and juvenile growth and survival, including temperature, salinity, dissolved oxygen, and food availability. Nursery habitat for winter flounder larvae and juveniles is typically saltwater coves, coastal salt ponds, estuaries, and protected embayments; although larvae and juveniles have also been found in open ocean areas such as Georges Bank and Nantucket shoals. Larvae are predominantly found in the upper reaches of estuaries in early spring, moving into the lower estuary later in the season.

Winter flounder lay up to 3.3 million demersal, adhesive eggs that are retained within their spawning grounds. Depending on temperature, larvae of approximately 3 mm in length hatch in two to three weeks. These larvae are planktonic at first, but transition to a bottom-oriented lifestyle over time. Around five to six weeks after hatching, the left eye of the larval flounder begins to migrate to the right side of the body. The “flounder-like” juveniles then settle onto the seafloor and move into saltwater coves, coastal salt ponds, estuaries, and protected bays, where they may grow up to 100 mm within the first year. Adult winter flounder may grow as large as 70 cm and reach ages of 15+ years. Growth varies across their distribution, with northern populations generally growing slower than those at the southern end of their range.

Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Pleuronectiformes
Family: Pleuronectidae
Genus: Pseudopleuronectes
Species: P. americanus

By 1963 it had been determined that Winter Flounder moved offshore when the water got above 15°C and returned to the shallows when the water cooled. Usually this would result in a winter/deeper/offshore and summer/shoaler/inshore pattern. However the inshore summer water temperature does not always reach beyond 15°C, in which case the Winter Flounder would remain inshore. The preferred temperature range was determined to be a very narrow 12-15°C, across several populations throughout the NW Atlantic.

This means a narrow depth range, accounting for the all-or-nothing nature of Winter Flounder catches, and confounding interpretation of catch rate (catch per unit effort, or CPUE) trends once the distributional range was known to the fishing industry. Thus CPUE declined drastically in the early years of the fishery, but by later years the fish locations could be predicted accurately enough to compensate for population decline. The narrow temperature preference was later (1988) disputed, it being argued that the offshore movement in summer was for the purpose of feeding. In the end both temperature and feeding appear relevant.

Southern Flounder

Southern flounder are found in rivers and estuaries along the Atlantic Coast from North Carolina to northern Florida, and from Tampa Bay, Florida along the Gulf coast into southern Texas. Their distribution is discontinuous around the southern tip of Florida, leading some biologists to wonder if there are two genetically separate natural stocks. Southern flounder are found in a wide range of salinities; adults have been captured in a range of 0 to 36 ppt (parts per thousand) salinity, and it is not uncommon to catch them by hook and line far inland on coastal rivers.

The southern (or armless) flounders are a small family, Achiropsettidae, of flounders found in Antarctic and sub-Antarctic waters. There are four genera, each with one species.

The broad flounder, Paralichthys squamilentus, is similar but is rarely found in inshore waters. Adults prefer depths of 100-220 meters. Juveniles are found in shallower water, but seldom in estuaries or bays. As the name implies, the broad flounder's body is wider, with the body width being half the length or greater.

Another 15 species of lefteye flounders are found in the northern Gulf of Mexico, but they are unlikely to be confused with the southern, gulf, or broad flounder.

The southern flounder generally prefers sandy - muddy bottoms throughout most of the estuary, but it can occur in channel and bay mouths and also frequents areas around piers, pilings, and rock jetties. Migrations to offshore spawning grounds begin in late fall at the onset of cold weather, and spawning is completed during winter months. They will lay in the sand around any natural structure, or around any of the numerous artificial reefs and wrecks. Spear-fishermen take some huge flounder around these wrecks in the winter months. This species is the prefect predator, lying in total camouflage on the bottom until unsuspecting prey wander within reach and are capture with lightning quick movements. Foods of this species include shrimp and fishes

• Scientific Name: Paralichthys lethostigma
• Common Names: flounder, mud flounder, plie (Louisiana French)
• Order: Pleuronectiformes
• Family: Paralichthyidae
• Population trend: stable

The southern flounder and Gulf flounder and other flatfish are compressed laterally and spend most of their life lying on the bottom or swimming along the bottom on their side. They have prominent eyes and a large mouth with large, sharp, pointed teeth.

Southern flounder and Gulf flounder are known as left-eye flounders; the eyes of the adults are always on the fish's left side. The opposite is true for other species of flounders, halibut, and all the species of soles, whose eyes are on the right side.

The left or "up" side of the southern and Gulf flounders is light olive brown to dark brown or nearly black, with many blotches and spots of darker and lighter color. The eyeless "down" size side is white or dusky. Gulf flounders are distinguished by three large dark eye-like spots, arranged in a triangle with a pair of spots about midway on the length of the fish and a third closer to the tail. Southern flounders may also have scattered large spots but they are much more diffuse and gradually disappear as the fish grows older. The scales are small. As described below, flounders can modify their coloration and patterning to match the bottom.

Flounder lying in ambush and partially buried on a sandy bottom. Click for a larger version.
Southern flounders are larger and live longer than Gulf flounders. Female southern flounders typically grow to about 28", while typical female Gulf flounders reach only about 18". Males of both species are smaller, typically reaching only 10 to 14" in length. After their first year of life, males spend most of their lives offshore, seldom venturing into estuaries and bays. Thus, the majority of flounders caught by anglers in inshore waters are females.

Flounders have small body cavities and lack a swim bladder, making it easier for them to maintain their position on the bottom.

VIDEO - Southern Flounder

Flounder

Flounder, any of numerous species of flatfishes belonging to the families Achiropsettidae.Included among the approximately 100 species of the family Pleuronectidae are the European flounder (Platichthys flesus), a marine and freshwater food and sport fish of Europe that grows to a length of 50 cm (20 inches) and weight of 2.7 kg (6 pounds); the starry flounder (Platichthys stellatus), a North Pacific species that averages about 9 kg (20 pounds) in weight; and the winter flounder (Pseudopleuronectes americanus), an American Atlantic food fish, growing to about 60 cm (23 inches) in length. Flounders in that family typically have the eyes and colouring on the right side.

Flounders are a group of flatfish species. In the families Bothidae and Paralichthyidae, which together contain more than 240 species, the better-known flounders include the summer flounder (Paralichthys dentatus), an American Atlantic food fish growing to about 90 cm (35 inches); the peacock flounder (Bothus lunatus), a tropical American Atlantic species attractively marked with many pale blue spots and rings; the brill (Scophthalmus rhombus), a relatively large commercial European species, reaching a length of 75 cm (29 inches); and the dusky flounder (Syacium papillosum), a tropical western Atlantic species. Flounders in those families typically have eyes and colouring on the left side.

In its life cycle, an adult flounder has two eyes on one side of its head, and at hatching one eye is on each side of its head. One eye migrates to the other side of the body through a metamorphosis as it grows from larval to juvenile stage. As an adult, a flounder changes its habits and camouflages itself by lying on the bottom of the ocean floor as protection against predators. As a result, the eyes are then on the side which faces up. The side to which the eyes migrate is dependent on the species type.

The flounder is a typical flatfish with flattened fins that wrap around the oval-shaped body. Its eyes are positioned on the right side of the head (if you imagine the fish swimming upright) but, identification can be quite difficult because

•  some have been found with eyes directed towards the left
•  flounders have been known to interbreed (hybridise) with plaice giving rise to coloured variations
•  there are also flounders which have undersides exactly the same colour as their backs (normally they have white undersides).

The tail of a flounder is quite square at its end and there are bony tubercles around both sides of the body, at the bases of both the elongated dorsal and anal fins.
Flounders are very widely distributed around the coast of Britain. It lives from the shoreline down to depths around 165 feet deep, favouring muddy bottoms but will also live over sandy bottoms.

Flounders are amazingly tolerant of variations in the salt content of water. They can be found living in the sea, they can be found living in estuaries where slat water meets fresh, and they can even be found (and caught) in the freshwater of rivers well away from the sea shore. Flounders can be caught anywhere with flat shallow beaches and scars favoured spots. Although they can be caught at any time, by far the most prolific period for flounder fishing is within the first 3 hours of an incoming tide.

As far as anglers are concerned the flounder is primarily a spring, summer and autumn species as it is at these times of the year when flounders live within casting range. In the depths of winter they migrate into the warmer and deeper water well away from the shoreline. Flounders are at their most abundant from mid spring through until late summer. The onset of warmer weather sees the flounder arrive en masse for a summer feeding frenzy.